Electrical grounding system for instruments used in assembling disc drives

ABSTRACT

An instrument (12) separated from ground by a supradissipative resistance and having a surface (26) which is placed in electrical contact with a magnetic head of a disc drive assembly includes an electrically conductive receptacle (134) engaging and electrically connected proximate to the surface (26) of the instrument (12). The electrically conductive receptacle (134) is electrically coupled to ground for grounding the instrument (12) to prevent damage to the magnetic head caused by static discharge from the instrument (12).

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 08/445,183filed May 19, 1995, now abandoned.

This application is a §371 filing of PCT Application No. PCT/US/06854filed May 14, 1996, which claims priority of application Ser. No.08/445,183 filed May 19, 1995.

This application is related to application Ser. No. 08/723,261 filedSep. 30, 1996, which claims priority of application Ser. No. 08/445,183filed May 19, 1995.

BACKGROUND OF THE INVENTION

The present invention relates to devices and instruments for use inassembling a disc drive assembly and its sub-assemblies. In particular,the present invention relates to an electrical grounding deviceelectrically coupled to a dispenser for dispensing fluids, such as glueand epoxy, upon a surface of the disc drive assembly which is inelectrical contact with a magnetic head of the assembly.

The magnetic head stores and retrieves information on a magnetic disc.Several types of magnetic heads are currently in use, includingmetal-in-gap (MIG) heads, thin film (TF) heads and magnetoresistive (MR)heads. Due to the continual drive to increase storage density inmagnetic disc drive units, magnetic heads have become increasinglyadvanced and sensitive.

Typically, a magnetic head consists of a slider and a transducer. Theslider carries the transducer and flies over the surface of the magneticdisc as the disc rotates. The transducer reads and/or writes to themagnetic disc. Electric signals are provided to and received from thetransducer via conductors which are typically twisted wires. A glue,such as fluid epoxy, attaches wires or tacks the wires to bonding padsand sides of the slider. This tacking process, otherwise known asconformal coating, actually coats the wire where the wire is attached tothe slider. As a result, the conformal coating process prevents thewires from being pulled loose and also protects the wires fromcorrosion.

The slider of the magnetic head is supported above the magnetic disc aspart of a head/gimbal assembly. As described in Hagen U.S. Pat. No.5,027,239, herein incorporated by reference, the head-gimbal assemblytypically includes at least one support arm, a load beam, a gimbal andthe magnetic head discussed above. The support arm is attached to theload beam by a well-known technique referred to as swaging or ballstaking. The load arm carries the load beam. The load beam is attached,preferably by laser welding, to the gimbal. Lastly, the gimbal ispreferably glued to the slider of the magnetic head by fluid epoxy orother conventional adhesive materials. Typically, the fluid, such asglue or fluid epoxy, applied to surfaces of the slider and the gimbal isdispensed onto the surface from a dispensing syringe which is positionedand controlled either manually or by an automated process.

IBM TDB vol. 37, no. 2A, February 1994, entitled "Hand tools groundingfor manufacturing sensitive parts assemblies" discloses a kit forfitting to an existing small hand tool such as a commercial screwdriverwith a plastic handle, the kit comprising a number of fingers extendingfrom a central aperture through which the end of the tool is inserted.The fingers are stuck to the handle of the tool and compriseelectrostatic discharge material for preventing static build-up at theend of the tool.

FR-A-2646491 discloses a suction tube for grasping and transportingsemiconductor devices having a conductive insert for making anelectrical connection between the end of the tool contacting thesemiconductor devices and a carbon fibre body of the tool, such as toconduct away from the tool end electrostatic charge.

Neither of these disclosures are concerned with a dispenser fordispensing fluid to surfaces of a disk drive assembly. Such dispensersfrequently suffer from a problem of electrostatic charge build-up at thesurface of the dispenser close to the disk drive assembly.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an assembly forcoupling to a dispenser for preventing the build-up of electrostaticcharge.

In accordance with a first aspect of the invention, there is provided asurface for assembling a disc drive assembly, wherein the syringe isseparated from ground by a supradissipative resistance and wherein thesyringe has a needle which is placed in electrical contact with asurface of the assembly in electrical contact with magnetic head of theassembly, characterized by:

an electrically conductive receptacle engaging and electricallyconnected to the needle; and

electrically conductive means electrically connected between theconductive receptacle and ground, for grounding the syringe to preventdamage to the magnetic head caused by static discharge from the syringe.

In a further aspect, the invention provides a method for electricallygrounding a hand-held syringe used for assembling a disc drive assembly,wherein the syringe has a needle which is placed in electrical contactwith a magnetic head of the disc drive assembly, the method comprising:

mounting an electrically conductive attachment on the syringe, theattachment having an electrically conductive receptacle in electricalcontact with the needle and an electrically conductive means inelectrical contact with the conductive receptacle, the conductive meanshaving a configuration for being grasped by the hand of an operator;

wearing an electrically conductive glove over the hand;

wearing an electrically conductive wrist strap, wherein the wrist strapis in contact with the skin of the operator and is electricallygrounded; and

grasping the electrically conductive means with the electricallyconductive glove when the needle is positioned in electrical contactwith the magnetic head.

The present invention is an electrical grounding system for devices orinstruments used for assembling portions of a disc drive assembly whichare in electrical contact with a magnetic head of the assembly. Thepresent invention includes conductive means electrically connectedproximate to a surface of a device which is placed in contact with thesurface of the assembly in electrical contact with the magnetic head ofthe assembly. The conductive means are electrically grounded to drainstatic charge build-up from the device to prevent damage to the magnetichead caused by static discharge from the device.

The grounding system illustrated is for use with a dispenser having anopening through which fluids, such as coatings, glue and epoxy, aredispensed onto the surface of the disc drive assembly or itssub-assemblies. The illustrated grounding system includes anelectrically conductive receptacle electrically connected adjacent tothe opening of the dispenser for electrically grounding the surface ofthe dispenser most likely to come into electrical contact with themagnetic head of the assembly. The electrically conductive receptacle isgrounded to drain static charge build-up from the dispenser.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an electrical grounding system includinga grounding attachment coupled to a dispenser.

FIG. 2 is an enlarged fragmentary exploded view of the dispenser and thegrounding attachment of FIG. 1.

FIG. 3 is an exploded perspective view of the grounding attachment ofFIG. 1.

FIG. 4 is a cross-sectional view of a receptacle of the groundingattachment with the dispenser partially disposed within the receptacle.

FIG. 5 is an enlarged fragmentary exploded view of an alternateembodiment of the grounding attachment and the receptacle.

FIG. 6 is a cross-sectional view of the grounding attachment and thereceptacle of FIG. 5 with the dispenser partially disposed within thereceptacle.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 illustrates a device or instrument for use in assembling a discdrive assembly or its sub-assemblies. In particular, FIG. 1 illustratesan electrical grounding system 10 electrically coupled to dispenser 12.Dispenser 12 is an example of an instrument used for assembling a discdrive assembly. In particular, dispenser 12 meters and dispenses exactamounts of glue or coatings, such as fluid epoxy, to surfaces of themagnetic head, including the slider and the transducer, and the gimbal(not shown) to attach the slider to the gimbal and to apply a conformalcoating over wires coupled to the transducer and the slider of themagnetic head. The conformal coating provides the wire with strainrelease and prevents the wires from being pulled loose. The conformalcoating applied to the wires also prevents corrosion of the wires.Dispenser 12 preferably comprises a syringe supplied by E.F.D.Incorporated, 977 Waterman Avenue. East Providence. R.I. 02914.

Dispenser 12 generally includes barrel 14, dispensing tip 16, and piston18. Because dispenser 12 is used for assembling disc drives or theirsub-assemblies, each component of dispenser 12 is preferablynon-magnetic and contaminant free (i.e. excluding such elements ascarbon and silicone). Barrel 14 is generally cylindrical or tubular inshape and includes a first open end 20 and a second narrowing end 22opposite the first end. Barrel 14 acts as a reservoir and contains thefluid epoxy of dispenser 12. Barrel 14 is preferably transparent topermit amounts of fluid within barrel 14 to be visually detected. Barrel14 may have various diameters and may contain various amounts of fluidepoxy. In the example illustrated in FIG. 1, barrel 14 and the remainingcomponents of dispenser 12 are sized and configured for manualdispensing of epoxy from dispenser 12. As can be appreciated, barrel 14and dispenser 12 have any one of various sizes when fluid epoxy isdispensed by an automated process (not illustrated). Barrel 14 ispreferably formed from silicon free polypropylene to preventcontamination of the disc drive.

Dispensing tip 16 is sealedly coupled to second narrowing end 22 ofbarrel 14. Dispensing tip 16 includes hub 24 and tube or needle 26. Hub24 is fixedly secured about needle 26 and is configured for coupling tosecond narrowing end 22 of barrel 14. Preferably, hub 24 includesexterior threads for threadably engaging exterior threads defined by end22 of hub 24. As a result, dispensing tip 16 may be easily replaced.Alternatively, hub 24 of dispensing tip 16 is integrally formed as partof barrel 14. Hub 24 is preferably formed from a silicon freehomopolymer polypropylene with an ultra-violet block additive. Theultra-violet block additive is preferably colored to indicate a diameterof the opening defined by dispensing tip 16 through which fluid epoxy isdispensed.

Needle 26 is a tube having a highly controlled inner diameter fordispensing exact amounts of glue or epoxy. Needle 26 has an opening 28at one end thereof through which the fluid is dispensed. Although shownas having a uniform outer diameter and as having an opening at thedistal end, needle 26 may alternatively have a narrowing outer diameterand an opening through a sidewall of the tube. For contaminationconcerns, needle 26 is preferably formed from 304 stainlesssteel-passivated. Alternatively, needle 26 may be formed of any one of avariety of conductive materials. For purposes of this disclosure, theterm "conductive," hereinafter refers to any material that has anelectrical resistance from zero ohms to about 1.0×10¹¹ ohms. Needle 26and hub 24 define a highly controlled fluid conduit through which fluidepoxy from within barrel 14 is emitted out opening 28 by actuation ofpiston 18.

Piston 18 is conventionally known and includes a bulb (not shown) forinsertion into barrel 14. Actuation of piston 18 causes epoxy withinbarrel 14 to be dispensed out opening 28 of needle 26 onto a surface ofthe magnetic head or the gimbal. For illustration purposes, FIG. 1 showspiston 18 as being manually actuated. However, piston 18 mayalternatively be automatically operated by an automated process as isconventionally known. Furthermore, for more precise control of fluiddispensing, an air operated dispensing system, a timed-pulse airoperated dispensing system, or other conventionally known means may beused in place of piston 18 for forcing fluid out needle 26 of dispenser12.

Because dispenser 12 applies fluid epoxy to extremely small and preciselocations or surfaces of the magnetic head or gimbal, the needle ofdispenser 12 is often brought into very close or even physical contactwith the surface upon which the epoxy is being deposited. It has beendiscovered that because components of dispenser 12 are electricallyseparated from ground by a supradissipative resistance (i.e. aresistance greater than about 1.0×10¹¹ ohms), electrostatic chargebuilds up within the material of dispenser 12. As a result, theelectrostatic charge at needle 26 is or may be discharged when needle 26is positioned in close or physical contact with a surface upon whichepoxy is being deposited. Because the surfaces upon which the fluidepoxy are deposited are electrically connected or coupled to themagnetic head, the electrostatic discharge from needle 26 is alsoconducted to the magnetic head by direct electrical continuity ordielectric breakdown. It has been discovered that this electrostaticdischarge to the magnetic head may actually cause damage to advancedmagnetic heads which are extremely sensitive to even extremely lowvoltages. As a result, based upon this discovery, grounding system 10 isprovided for electrically grounding needle 26 to ensure that needle 26and the surface upon which epoxy is being deposited are at an equal ornear equal electrical potential.

Grounding system 10 electrically grounds conductive needle 26 ofdispenser 12 and permits static charge to be drained from needle 26.Grounding system 10 includes grounding attachment 30 and groundingconnection 32. Because grounding system 10 is used for groundinginstruments used in assembling disc drives or their sub-assemblies, eachcomponent of grounding system 10 is preferably non-magnetic andcontaminant free (i.e. excluding such elements as carbon and silicone).Grounding attachment 30 mounts upon dispenser 12 and generally includesreceptacle 34, conductive mounting member 36 and conductive arm 38.Receptacle 34 is made of a highly electrically conductive material andreceives or holds needle 26 of dispenser 12. Because needle 26 ispreferably made of stainless steel, which is electrically conductive,receptacle 34 is electrically connected adjacent to or proximate asurface of needle 26 most likely to come into close or actual physicalcontact with a surface of the magnetic head or gimbal. This surface ondispenser 12 is the surface of needle 26 adjacent opening 28 throughwhich fluid epoxy is dispensed. Receptacle 34 is grounded through arm38, mounting member 36 and ground connection 32. Preferably, receptacle34 is grounded to an AC ground. As a result, receptacle 34 electricallygrounds the surface of dispenser 12 most likely to come into contactwith the surface of the disc drive assembly that is electrically coupledto the sensitive magnetic head. Consequently, receptacle 34 preventsdamage to the magnetic head caused by electrostatic discharge fromneedle 26 of dispenser 12.

Mounting member 36 is configured for attachment to barrel 14 ofdispenser 12 and is made of a highly electrically conductive material.Mounting member 36 is preferably made of resilient spring stainlesssteel. Mounting member 36 is preferably configured for being releasablymounted to barrel 14 so that grounding attachment 30 may be removed fromdispenser 12 when barrel 14 is being refilled with fluid epoxy or whendispensing tip 16 is being replaced. Alternatively, mounting member 36may be fixedly secured to barrel 14. Mounting member 36 is electricallygrounded by ground connection 32. As a result, mounting member 36grounds and drains static charge build-up from barrel 14 of dispenser12. As shown by FIG. 1, mounting member 36 is preferably configured forbeing grasped by an operator's hand. Alternatively, when a machine orother automated process automatically dispenses fluid epoxy fromdispenser 12, mounting member 36 may have any one of a variety ofshapes.

Conductive arm 38 extends from mounting member 36 to receptacle 34 andis made of a highly electrically conductive material. Conductive arm 38is preferably made from spring stainless steel. Conductive arm 38establishes an electrical conductive path from receptacle 34 to mountingmember 36 and ultimately to ground through ground connection 32.

Ground connection 32 electrically grounds grounding attachment 30 andincludes conductive glove 40, wrist strap 42 and electrical conductor44. Conductive glove 40 is an electrically conductive glove sized forfitting upon an operator's hand. Preferably, glove 40 is made from asynthetic rubber possessing conductive properties such as Nitrilitesupplied by Ansell-Edmont Industrial Inc., 1300 Walnut Street, Box 6000,Coshocton. Ohio 43812-6000. Glove 40 prevents contaminating particlesand oils from the operator's hand from being deposited upon componentsof the disc drive assembly. Because conductive glove 40 is made of anelectrically conductive material, glove 40 conducts static chargebuild-up from grounding attachment 30 and needle 26 to tissue of theoperator when glove 40 is placed in contact with attachment 30. Glove 40conducts the static charge away from grounding attachment 30 through thetissue of the operator to wrist strap 42 which is electrically connectedto ground. As a result, glove 40 is electrically grounded via wriststrap 42. Alternatively, glove 40 may be formed from a material suchthat electrical charges may be conducted across and along the surface ofthe glove itself so that the glove may be directly electrically groundedby any conventional grounding connections.

Wrist strap 42 preferably encircles the operator's wrist and iselectrically connected to conductive glove 40. Wrist strap 42 is formedfrom a highly electrically conductive material. An example of such awrist strap is disclosed in Mykkanen, U.S. Pat. No. 4,373,175.Preferably, wrist strap 42 is a metal stretch band or woven wire band indirect electrical contact with the skin of the operator. As a result, anelectrical pathway is formed from glove 40 through the tissue of theoperator to wrist strap 42. Wrist strap 42 is electrically coupled toconductor 44. Conductor 44 is electrically connected to AC ground. Forsafety reasons, a 250 to 10 megohm resistor 45 is inserted in serieswith conductor 44. However, because the total resistance in seriesremains below 1.0×10¹¹ ohms, grounding of electrostatic charge is notnegated. As a result, conductive glove 40, wrist strap 42 and conductor44 of ground connection 32 provide a reliable electrical groundingconnection to grounding attachment 30 and needle 26 of dispenser 12during manual dispensing of fluid epoxy from dispenser 12.

Overall, grounding attachment 30, conductive glove 40, wrist strap 42and conductor 44 form an electrical pathway from needle 26 to ground fordraining static charge. The electrical pathway formed by groundingattachment 30, glove 40, the tissue of the operator, wrist 42 andconductor 44 has a maximum total resistance in series of about 1.0×10¹¹ohms. Preferably, the electrical pathway has as low of an electricalresistance as possible between needle 26 and ground. Because theelectrical pathway has a resistance in series at least within thedissipative range of resistance, grounding system 10 effectively drainsstatic charge from needle 26 of dispenser 12 and limits the amount ofvoltage existing at the tip of needle 26. In addition, grounding system10 provides a grounding connection that is reliable, ergonomic andcontaminant free.

As discussed above, fluid epoxy may alternatively be automaticallydispensed from dispenser 12 by an automated process. As a result,conductive glove 40 and wrist strap 42 of ground connection 32 may beomitted and conductor 44 may be directly electrically coupled togrounding attachment 30. In particular, conductor 44 may be directlyelectrically attached to mounting member 36 of attachment 30.Furthermore, when fluid epoxy is automatically dispensed from dispenser12, grounding attachment 30 may simply comprise receptacle 34, wherebyconductor 44 is directly electrically connected to receptacle 34. As cannow be appreciated, electrical grounding system 10 may have a variety ofdesigns and configurations for electrically grounding and drainingstatic charge build-up from instruments, such as dispenser 12 havingneedle 26, used for assembling disc drives and their sub-assemblies.

FIGS. 2-4 illustrate grounding attachment 30 in greater detail. FIG. 2is an enlarged fragmentary exploded view of grounding attachment 30partially removed from dispenser 12. FIG. 3 is an exploded perspectiveview of grounding attachment 30 completely removed from dispenser 12.FIG. 4 is a cross-sectional view of needle 26 partially inserted throughreceptacle 34. FIG. 2 illustrates receptacle 34 and conductive arm 38 ingreater detail. As best shown by FIG. 2, conductive arm 38 includes band50 and receptacle mount 52. Band 50 is made of a highly electricallyconductive material and extends between mounting member 36 andreceptacle mount 52. Preferably, band 50 is integrally formed withmounting member 36 and receptacle mount 52. Band 50 extends inward frommounting member 36 towards an axial center line of needle 26 anddispenser 12. As can be appreciated, band 50 and conductive arm 38 mayalternatively be fixedly mounted to mounting member 36 at a desiredangle with respect to mounting member 36. Band 50 is preferably formedfrom a rigid, yet resilient, material such as spring stainless steel.Because band 50 is preferably formed from a rigid, yet resilientconductive material, band 50 maintains receptacle mount 52 andreceptacle 34 at a substantially fixed position relative to mountingmember 36. Because band 50 maintains receptacle mount 52 and receptacle34 at a substantially fixed position relative to mounting member 36,receptacle 34 is repositioned in substantial alignment with needle 26.As a result, grounding attachment 30 may be more easily mounted todispenser 12. In addition, because band 50 extends inward towards theaxial center line of needle 26 of dispenser 12, conductive arm 38 doesnot impair the vision of the operator when manually dispensing fluidsfrom dispenser 12. Because band 50 is rigid, yet resilient, band 50 isdurable as well. Consequently, band 50 enables grounding attachment 30to be repeatedly removed from dispenser 12 when dispenser 12 is beingrefilled or when dispensing tip 16 is being replaced and also permitsgrounding attachment 32 to be remounted upon dispenser 12 for reuse.Alternatively, conductive arm may comprise any well known conductingstructure such as a conductive wire.

Receptacle mount 52 is preferably formed by bending band 50 at an angletowards the axial center line of dispenser 12. Receptacle mount 52 ispreferably formed from a highly electrically conductive material(preferably the same material as that of band 50) and defines aperture54. Aperture 54 has a center in alignment with the axial center line ofneedle 20 of dispenser 12. Aperture 54 preferably has a diameter sizedfor the reception of receptacle 34 through which needle 26 extends.

As shown by FIGS. 2 and 4, receptacle 34 includes shell 58, capturewasher 60 and contact 62 (shown only in FIG. 4). Shell 58 is a generallytubular shaped member made of a highly electrically conductive materialsuch as a brass alloy. Shell 58 is preferably tin plated. Shell 58 has afirst outer diameter 66 which widens to a second outer diameter 68 toform shoulder 70. Outer diameter 66 is sized for being received andextending through aperture 54 of receptacle mount 52. Shell 58 ofreceptacle 34 is preferably press fit in receptacle mount 52. However,outer diameter 68 is preferably sized larger than the diameter ofaperture 54 so that shoulder 70 abuts receptacle mount 52.

Capture washer 60 is a conventional washer made of highly electricallyconductive material, preferably tin plated brass, and defines an innerdiameter 74. Inner diameter 74 is sized for receiving in close toleranceouter diameter 66 of shell 58. Because both capture washer 60 andreceptacle shell 58 are preferably formed from tin plated brass,receptacle shell 58 and washer 60 are easily soldered together at lowtemperatures. As a result, capture washer 60 mounts receptacle shell 58of receptacle 34 to receptacle mount 52 of conductive arm 38 without thehigh heat which would otherwise be required for silver solderingreceptacle 34 directly to stainless steel mount 52. It has beendiscovered that the extreme heat required for silver solderingreceptacle 34 to stainless steel mount 52 causes oxidation and annealingof contact 62 and reduces electrical conductivity. As a furtherassurance of electrical contact between receptacle 34 and receptaclemount 52, capture washer 60 and receptacle shell 58 are soldered to eachother so that shoulder 70 of shell 58 and washer 60 are flush and inabutting contact with receptacle mount 52. Because washer 60 merelycaptures receptacle shell 58 to mount 52, shell 58 and washer 60 may beeasily removed by reheating the solder and replaced if necessary,thereby extending the useful and reusable life of grounding attachment30. In addition, receptacle 34 is securely held in place with respect tothe axial center line of needle 26 and dispenser 12 for ease of mountingand removing grounding attachment 30 to and from needle 26 and dispenser12.

As shown by FIG. 4, shell 58 further defines an inner diameter 80 sizedfor the reception of contact 62 and needle 26. Preferably, a surface ofinner diameter 80 is tin plated nickel. Alternatively, the surface maycomprise gold plated nickel. Contact 62 is formed from a highlyelectrically conductive resilient material such as a beryllium copperalloy. Preferably contact 62 has an outer diameter 82 sized so thatcontact 62 may be captivated within the inner diameter 80 of shell 58.The surface defining the outer diameter 82 is preferably tin platednickel. Alternatively, the surface may be formed from gold platednickel. As a result, contact 62 is securely electrically coupled toshell 58 to provide reliable electrical connection. Contact 62 definesan interior passage centrally extending through contact 62 and shell 58.

Contact 62 further includes a plurality of prongs or leaves 84. Leaves84 integrally extend from an end of contact 62 into an interior of shell58. Leaves 84 are angled towards an axial center line of contact 62.Leaves 84 are preferably formed from a resilient material having amemory such that upon insertion of needle 26 into the passage defined bycontact 62, leaves 84 grasp needle 26 to axially center needle 26 and toinsure a reliable electrical connection or continuity of contact betweenneedle 26 and contact 62 without the need for soldering needle 26 toreceptacle 34. Thus, leaves 84 allow needle 26 to be removed, enablinggrounding attachment 30 to be reused.

Furthermore, because the force used to insert and remove needle 26 fromcontact 62 of receptacle 34 is distributed to each of the plurality ofleaves, contact 62 is less likely to be damaged upon repeated insertionand removal of needle 26 into and out of receptacle 34. Because needle26 is inserted concentrically through contact 62 and shell 58, leaves 84of contact 62 and needle 26 itself are less likely to be damaged fromincorrect or misaligned insertion of needle 26. As a result, groundingattachment 30 may be removed from dispenser 12 while dispenser 12 isbeing filled or when dispensing tip 16 is being replaced so thatattachment 30 may be reused. Shell 58 and contact 62 preferably comprisepin receptacles conventionally used in circuit boards and supplied byMill-Max Manufacturing Corporation, P.O. Box 300, 190 Pine Hollow Road,Oyster Bay, N.Y. 11771-0300.

As best shown by FIG. 3, mounting member 36 is preferably an elongatedsleeve 88 having an inner diameter configured for attachment to barrel14 of dispenser 12 (shown in FIG. 1). Sleeve 88 has an inner diametersized for at partially surrounding barrel 14 of dispenser 12.Preferably, the inner diameter of sleeve 88 is sized in close tolerancewith an outer diameter of barrel 14 so that sleeve 88 remains in placeand in contact with barrel 14 unless forcefully removed. In thepreferred embodiment, sleeve 88 is C-shaped so that sleeve 88 may betemporarily expanded for removal of sleeve 88 and grounding attachment30 from dispenser 12. In addition, because sleeve 88 is C-shaped, sleeve88 allows the operator to visually inspect barrel 14 to detect theamount of epoxy remaining within barrel 14 of dispenser 12. Sleeve 88 ispreferably formed from a highly electrically conductive material whichis resilient and has a shape memory such as spring stainless steel. Whengrounding attachment 30 is used in conjunction with glove 40, wriststrap 42 and conductor 44 (manual dispensing), sleeve 88 preferably hasa surface area sized and configured for grasping by an operator's handwithin glove 40. Alternatively, when grounding attachment 30 is used inconjunction with an automated dispensing process, sleeve 88 mayadditionally include an electrical connection tab 92 as shown in FIG. 3.Tab 92 integrally projects outward and away from sleeve 88 and permitsgrounding conductor (not shown) to be easily attached to groundingattachment 30. As can be appreciated, various mechanisms may be used toelectrically ground grounding attachment 30.

FIGS. 5 and 6 illustrate an alternate embodiment (grounding attachment130) of grounding attachment 30 shown in FIGS. 2-4. FIG. 5 is anenlarged fragmentary exploded perspective view of needle 26 of dispenser12 partially extending through and electrically coupled to groundingattachment 130. FIG. 6 is a cross-sectional view of needle 26 insertedthrough and electrically connected to receptacle 134. For ease ofillustration, those elements of FIGS. 5 and 6 which are the same asthose elements of FIGS. 2-4 are numbered similarly.

As best shown by FIG. 5, receptacle 34 is replaced with receptacle 134and conductive arm 38 is replaced with conductive arm 138. Conductivearm 138 is similar to conductive 38 except that receptacle mount 52 isreplaced with receptacle mount 152. Similar to receptacle mount 52,receptacle mount 152 extends inward towards an axial center line ofneedle 26 and dispenser 12. However, as shown by FIG. 5, receptaclemount 152 is integrally formed as part of receptacle 134. Alternatively,the clip of receptacle 134 may be mounted to conductive arm 138.Receptacle mount 152 directly contacts needle 26 of dispenser 12.

Receptacle 134 generally comprises a clip configured for holding needle26. In the illustrated embodiment, the clip of receptacle 134 is formedby cutting an inverted U-shaped incision or slot 194 to create a finger196. Slot 194 receives needle 26 of dispenser 12. However, slot 194 ispreferably sized so as to have a width on either side of finger 196 lessthan an outer diameter of needle 26. Slot 194 is preferably formed by anelectrical cutting process known as EDM. Finger 196 is preferably formedfrom a highly electrically conductive resilient material. Finger 196 ispreferably formed from the same material as band 50 of conductive arm138.

As best shown by FIG. 6, because the width of slot 194 on either side offinger 196 is sized smaller than the outer diameter of needle 26,insertion of needle 26 through slot 194 temporarily deflects finger 196sideways so that finger 196 pivots left or right depending upon howneedle 26 is inserted. Because finger 196 is resilient, finger 196applies a force against the side surface of needle 26 to pressure orclamp needle 26 against receptacle mount 152. Consequently, the clipformed by slot 194 and finger 196 securely holds needle 26 in place andinsures a reliable and consistent electrical connection between needle26 and receptacle 134 of grounding attachment 130. As can beappreciated, the clip formed by receptacle 34, 134 may have a variety ofalternate configurations and designs for establishing a reliable,continuous electrical connection between needle 26 and groundingattachment 30, 130 and for securing needle 26 in place.

In conclusion, grounding system 10 provides a reliable, continuouselectrical path or circuit from needle 26 of dispenser 12 throughgrounding attachment 30, 130 and ground connection 32 to AC ground. Thiselectrical pathway has a maximum resistance in series of about 1.0×10¹¹ohms. Because the overall resistance in series of the electrical pathwayformed by grounding system 10 is within the dissipative range, groundingsystem 10 effectively drains static charge and minimizes or eliminatesvoltages existing at needle 26. Preferably, grounding system 10 reducesvoltages at needle 26 to levels below allowable voltage levels basedupon the sensitivity of the magnetic head to voltage. It has been foundthat the above disclosed grounding system may reduce voltages to amaximum of about three volts. As a result, grounding system 10 preventsdamage to the magnetic head during assembly caused by electrostaticdischarges from needle 26 of dispenser 12. At the same time, groundingsystem 10 does not interfere with the operator's use of dispenser 12 andis extremely ergonomic. In addition, grounding system 10 does notcontaminate components of the disc drive assembly being assembled andpermits easy determination of the amount of fluids within dispenser 12.As can be appreciated, grounding system 10 may be easily adapted tovarious other instruments used during assembly of disc drive componentswhich are in electrical contact with the magnetic head.

Although the present invention has been described with reference topreferred embodiments, workers skilled in the art will recognize thatchanges may be made in form and detail without departing from the spiritand scope of the invention.

What is claimed is:
 1. A syringe for assembling a disc drive assembly,wherein the syringe is separated from ground by a supradissipativeresistance and wherein the syringe has a needle which is placed incontact with a surface of the assembly in electrical contact with amagnetic head of the assembly, characterized by:an electricallyconductive receptacle engaging and electrically connected to the needle;and electrically conductive means electrically connected between theconductive receptacle and ground for grounding the device to preventdamage to the magnetic head caused by static discharge from the device.2. The improved device of claim 1 wherein the receptacle includes:anelectrically conductive tube through which the needle is inserted. 3.The improved device of claim 3 wherein the electrically conductive tubeincludes:at least one electrically conductive prong within the tube,wherein the prong is resiliently biased into contact with the needle. 4.The improved device of claim 1 wherein the receptacle includes:a clipconfigured for holding the needle.
 5. The improved device of claim 4wherein the clip comprises:a body defining an opening for receiving theneedle; and a finger projecting from the body into the opening, whereinthe finger clamps the needle against the body.
 6. The improved device ofclaim 1 wherein the syringe includes a tube having a narrowing endthrough which the needle projects and wherein the electricallyconductive means includes:an electrically conductive mounting memberconfigured for attachment to the tube; and an electrically conductivearm extending from the mounting member to the receptacle.
 7. Theimproved device of claim 6 wherein the electrically conductive mountingmember includes:an electrically conductive sleeve configured for atleast partially surrounding the dispenser tube.
 8. The improved deviceof claim 7 wherein the electrically conductive sleeve is substantiallyC-shaped for partially encircling the dispenser tube.
 9. The improveddevice of claim 6 wherein the electrically conductive arm comprises:arigid band fixedly coupled to the mounting member and the receptacle.10. A fluid dispensing system for dispensing fluids onto a disc drivesurface in electrical contact with a magnetic head, the systemcomprising:a syringe having a conductive needle through which fluids aredispensed onto the disc drive surface; an electrically conductivereceptacle engaging the needle; and electrically conductive meanselectrically connected between the conductive receptacle and ground; forelectrically grounding the conductive surface to prevent damage to themagnetic head caused by static discharge from the conductive surface.11. The system of claim 10 wherein the electrically conductive meansincludes:an electrically conductive mounting member configured forattachment to an upper portion of the dispenser; and an electricallyconductive arm extending from the mounting member to the receptacle. 12.The system of claim 11 wherein the electrically conductive armincludes:an electrically conductive rigid band fixedly coupled to themounting member and the receptacle.
 13. In a dispenser having aconductive needle through which fluids are dispensed onto a disc drivesurface in electrical contact with a magnetic head, an improvementcomprising:an electrically conductive receptacle engaging andelectrically connected to the needle; and electrical conductive meanselectrically connected to the conductive receptacle for electricallygrounding the receptacle, to prevent damage to the magnetic head causedby static discharge from the conductive surface.
 14. The device of claim13 wherein the receptacle includes:an electrically conductive tubethrough which the needle is inserted.
 15. The improved device of claim14 wherein the electrically conductive tube includes:at least oneelectrically conductive prong within the tube, wherein the prong isresiliently biased into contact with the needle.
 16. The device of claim13 wherein the receptacle includes a clip configured for holding theneedle.
 17. The device of claim 16 wherein the clip includes:a bodydefining an opening for receiving the needle; and a finger projectingfrom the body into the opening, wherein the finger clamps the needleagainst the body.
 18. The device of claim 17 wherein the dispensercomprises a tube having a narrowing end through which the needleprojects and wherein the electrical conductive means includes:anelectrically conductive mounting member configured for attachment to thetube; and an electrically conductive arm extending from the mountingmember to the receptacle.
 19. The device of claim 18 wherein theelectrically conductive mounting member includes:an electricallyconductive sleeve configured for at least partially surrounding thedispenser tube.
 20. The device of claim 19 wherein the electricallyconductive sleeve is substantially C-shaped for partially encircling thedispenser tube.
 21. The device of claim 18 wherein the electricalconductive means further includes:an electrically conductive glove forbeing placed in electrical contact with the mounting member, wherein theglove is electrically connected to ground.
 22. The device of claim 21wherein the electrical conductive means further includes:an electricallyconductive wrist strap for being worn by an operator adjacent tissue ofthe operator, wherein the wrist strap is electrically connected to theglove through the operator's tissue; and an electrical conductorextending from the wrist strap to ground.
 23. A system for applyingfluids onto a surface in electrical contact with a magnetic head, thesystem comprising:a syringe having a tube through which fluid isdispensed onto the surface and a barrel for being grasped by anoperator; an electrically conductive attachment coupled to the syringe,the attachment including: an electrically conductive receptacle engagingand electrically connected to the tube; an electrically conductivemounting member configured for attachment to the barrel of the syringe;and an electrical conductor extending from the mounting member to thereceptacle; and an electrically conductive glove for being worn by theoperator and for electrically contacting the electrically conductivemounting member, wherein the electrically conductive glove is grounded.24. The system of claim 23 further including:an electrically groundedwrist-strap electrically connected to the electrically conductive glove.25. The system of claim 24 wherein the electrically conductiveattachment, the electrically conductive glove and the electricallygrounded wrist strap have a maximum total resistance in series of about1.0×10¹¹ ohms.
 26. The system of claim 23 wherein the electricallyconductive mounting member includes:an electrically conductive sleeveconfigured for at least partially surrounding the barrel of the syringe.27. A method for electrically grounding a hand-held syringe used forassembling a disc drive assembly, wherein the syringe has a needle whichis placed in electrical contact with a magnetic head of the disc driveassembly, the method comprising:mounting an electrically conductiveattachment on a surface of the syringe, the attachment having anelectrically conductive receptacle in electrical contact with the needleand an electrically conductive means in electrical contact with theconductive receptacle, the conductive means having a configuration forbeing grasped by the hand of an operator; wearing an electricallyconductive glove over the hand; wearing an electrically conductive wriststrap, wherein the wrist strap is in contact with the skin of theoperator and is electrically grounded; and grasping the electricallyconductive means with the electrically conductive glove when the needleis positioned in electrical contact with the magnetic head.